FLUCTUATIONS OF OPTICAL AND ELECTRICAL PARAMETERS OF DISTRIBUTED FEEDBACK LASERS AND THEIR RELIABILITY

Abstract

Comprehensive experimental optical and electrical noises and their mutual correlation factor characteristic investigations of distributed feedback (DFB) InGaAsP / InP multiple-quantum well laser diodes (LDs) are presented. At the lasing operation, both optical and electrical noises of DFB LDs are 1/f type and are caused by the defects. Worse operation characteristics and short lifetime of some LDs are caused by the presence of defects in the interfaces with the active region. These defects increase leakage that leads to the larger LD threshold; and, during the ageing, they migrate, form clusters and deteriorate the laser characteristics. Noise characteristics (especially the correlation factor between optical and electrical fluctuations at the threshold) have been found to be suitable for semiconductor lasers quality and reliability prediction.